The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides a fiber optic differential pressure sensor.
It is known to use an optical fiber to detect strain in a member due to pressure applied to the member in a well. The detected strain may then be used to determine the pressure applied to the member.
However, prior optical fiber sensors have not been able to detect certain differential pressures in a well, such as a difference between pressures in two different portions of a flow passage in a tubing string. The ability to detect differential pressures in a well, especially the difference between two variable pressures in a well, would enable certain fluid properties to be determined more directly and without the need to use multiple sensors to individually detect the various pressures. A single sensor capable of directly detecting a differential pressure would also be more accurate than calculating the difference between different readings from multiple absolute or gauge pressure sensors.
Therefore, it may be seen that it would be beneficial to provide improved differential pressure sensors and sensor systems for use in wells. These sensors and sensor systems could find use in other applications, as well.